Low screen resolution and invalid EDID.

English Hardware
1

**Hi! **:wink:
I just installed Open SUSE for giving it a try.

The problem I’m facing is the low screen resolution (with amdgpu from reposirories).
Screen resolution is at 1024X768 and it should be at 1360X768.
Also when starting, the system complains for an invalid EDID.
(radeon_vga_detect ERROR VGA-1 probed a monitor but no-invalid EDID).
I have a Samsung Syncmaster, that is known to be problematic with EDID.

IS there any control panel-gui, for amdgpu driver?
At past I use to correct this behavior, editing xorg.conf, but I’m not sure how to do it at present time.
Any hints?
**TIA! **:slight_smile:
T.

2

I am currently struggling with this too.
This is a matter of the kernel mode-setting driver, not the X server.
To begin with, add this parameter to the end of GRUB_CMDLINE_LINUX_DEFAULT in file /etc/default/grub

video=VGA-1:1360x768

Then of course do

grub2-mkconfig -o /boot/grub2/grub.cfg
3

THANKS achaios!!! :wink:
Glad to see, that I’m not the only one who faced this problem! :slight_smile:

I tried it, but nothing changed.
Still stuck in low-res. :question:

4

Try adding the desired display resolution with xrandr as explained here…

https://wiki.archlinux.org/index.php/xrandr#Adding_undetected_resolutions

Once you have it working, you can make it persistent by adding to an executable autostart script for your desktop environment.

5

THANKS!!! :wink:
I’ll try it!

6

Just be aware that this will only take effect after logging in, and if using GNOME then monitors.xml needs to be removed as well (mentioned in the wiki page).

7

Thalassius it seems to me that you have a monitor with a faulty EDID block (hopefully just bad CRC)
If you post your dmesg I might be able to fix it properly and then have the kernel load the good EDID from a file.
This would make your monitor work throughout the system as it should in all of the virtual terminals.

(I am writting from Psarofai of Patras at this moment)

8

To wrap it up for future visitors, the best solution I have found for this problem is:

  1. Extract the EDID block in ascii hex from dmesg. Remove spaces between digits.
  2. Install program wxEDID from OBS.
  3. Import the file previously created, and examine it. Hopefully it is just a CRC error.
  4. Save the corrected EDID file in binary form, usually 128 bytes or maybe 256.
  5. Copy the file to /lib/firmware/edid/.
  6. Modify /etc/default/grub to contain a line looking like this
GRUB_CMDLINE_LINUX_DEFAULT="splash=verbose showopts video=VGA-1:1280x1024-24@75e drm_kms_helper.edid_firmware=VGA-1:edid/flatron.bin"

grub2-mkconfig -o /boot/grub2/grub.cfg
  1. Reboot

Enjoy your new monitor.
There is only one caveat though. The character ‘e’ at the end of the ‘video’ parameter will make the specific video output to be considered as permanently connected, ie no hotplugging monitors into this one. If you replace the monitor, remember to remove the kernel options.
If your EDID block is completely corrupted or non existent you can use a generic one.
There are permanent hardware fixes for such monitors on the web, but they are beyong the scope of this forum I believe.

9

Similar documented here…

https://wiki.archlinux.org/index.php/kernel_mode_setting#Forcing_modes_and_EDID